Developmental exposure to real-life environmental chemical mixture programs a testicular dysgenesis syndrome-like phenotype in prepubertal lambs

Current declines in male reproductive health may, in part, be driven by anthropogenic environmental chemical (EC) exposure. Using a biosolids treated pasture (BTP) sheep model, this study examined the effects of gestational exposure to a translationally relevant EC mixture. Testes of 8-week-old ram lambs from mothers exposed to BTP during pregnancy contained fewer germ cells and had a greater proportion of Sertoli-cell-only seminiferous tubules. This concurs with previous published data from fetuses and neonatal lambs from mothers exposed to BTP. Comparison between the testicular transcriptome of biosolids lambs and human testicular dysgenesis syndrome (TDS) patients indicated common changes in genes involved in apoptotic and mTOR signalling. Gene expression data and immunohistochemistry indicated increased HIF1α activation and nuclear localisation in Leydig cells of BTP exposed animals. As HIF1α is reported to disrupt testosterone synthesis, these results provide a potential mechanism for the pathogenesis of this testicular phenotype, and TDS in humans.

Revisiting the hybridization processes in the Triatoma brasiliensis complex (Hemiptera, Triatominae): Interspecific genomic compatibility point to a possible recent diversification of the species grouped in this monophyletic complex

Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b. brasiliensis, T. b. macromelasoma, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae and T. sherlocki. The specific status of several species grouped in the T. brasiliensis complex was confirmed from experimental crossing and analysis of reproductive barriers. Thus, we perform interspecific experimental crosses between T. lenti and other species and subspecies of the T. brasiliensis complex and perform morphological analysis of the gonads and cytogenetic analysis in the homeologous chromosomes of the hybrids of first generation (F1). Besides that, we rescue all the literature data associated with the study of reproductive barriers in this monophyletic complex of species and subspecies. For all crosses performed between T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis and T. melanica with T. lenti, interspecific copulas occurred (showing absence of mechanical isolation), hybrids were obtained, none of the male hybrids presented the phenomenon of gonadal dysgenesis and 100% pairing between the chromosomes homeologous of the hybrids was observed. Thus, we demonstrate that there are no pre-zygotic reproductive barriers installed between T. lenti and the species and subspecies of the T. brasiliensis complex. In addition, we demonstrate that the hybrids obtained between these crosses have high genomic compatibility and the absence of gonadal dysgenesis. These results point to reproductive compatibility between T. lenti and species and subspecies of the T. brasiliensis complex (confirming its inclusion in the complex) and lead us to suggest a possible recent diversification of the taxa of this monophyletic group.

Mutations in the desert hedgehog (DHH) gene in the disorders of sexual differentiation and male infertility

PURPOSE

To identify the contribution of mutations in the Desert Hedgehog (DHH) gene to the disorders of sexual differentiation (DSD) and male infertility.

METHODS

The study included a total 430 subjects, including 47 gonadal dysgenesis cases, 6 patients with undescended testis and infertility characterized by azoospermia, 125 infertile male patients characterized by oligoasthenozoospermia, 24 patients with oligoasthenoteratozoospermia, and 200 ethnically matched normozoospermic fertile men who had fathered a child in the last two years. Sequencing of the complete coding region of the DHH gene was undertaken to find its contribution to the DSD and male infertility.

RESULTS

We observed four novel mutations in the DHH gene in the cases with different reproductive anomalies. A synonymous substitution, c. 543C>T (p.His181His) was observed in 6.6% oligoasthenozoospermic infertile males and 1.5% normozoospermic fertile control samples (RR = 4.4077, 95%CI 1.19-16.29). Another synonymous substitution, c.990G>A (p.Ala330Ala) was observed in an infertile patient with unilateral undescended testis (case #12). Insertion of G at c.1156insG (p.Arg385fs) was observed in a case with bilateral undescended testis and azoospermia (case #23). In gonadal dysgenesis category, two mutations, insertion of G at c.1156insG (p.Arg385fs) and c.997A>G (p.Thr333Ala) substitution were observed in one case (case #34). These mutations were completely absent in control samples.

CONCLUSION

Mutations in the DHH gene impact reproduction with mild mutations affecting fertility, and severe or multiple mutations resulting in gonadal dysgenesis.

Breast Cancer and Major Deviations of Genetic and Gender-related Structures and Function

We have searched the literature for information on the risk of breast cancer (BC) in relation to gender, breast development, and gonadal function in the following 8 populations: 1) females with the Turner syndrome (45, XO); 2) females and males with congenital hypogonadotropic hypogonadism and the Kallmann syndrome; 3) pure gonadal dysgenesis (PGD) in genotypic and phenotypic females and genotypic males (Swyer syndrome); 4) males with the Klinefelter syndrome (47, XXY); 5) male-to-female transgender individuals; 6) female-to-male transgender individuals; 7) genotypic males, but phenotypic females with the complete androgen insensitivity syndrome, and 8) females with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome (müllerian agenesis). Based on this search, we have drawn 3 major conclusions. First, the presence of a Y chromosome protects against the development of BC, even when female-size breasts and female-level estrogens are present. Second, without menstrual cycles, BC hardly occurs with an incidence comparable to males. There is a strong correlation between the lifetime number of menstrual cycles and the risk of BC. In our populations the BC risk in genetic females not exposed to progesterone (P4) is very low and comparable to males. Third, BC has been reported only once in genetic females with MRKH syndrome who have normal breasts and ovulating ovaries with normal levels of estrogens and P4. We hypothesize that the oncogenic glycoprotein WNT family member 4 is the link between the genetic cause of MRKH and the absence of BC women with MRKH syndrome.

The gene encoding the ketogenic enzyme HMGCS2 displays a unique expression during gonad development in mice

Disorders/differences of sex development (DSD) cause profound psychological and reproductive consequences for the affected individuals, however, most are still unexplained at the molecular level. Here, we present a novel gene, 3-hydroxy-3-methylglutaryl coenzyme A synthase 2 (HMGCS2), encoding a metabolic enzyme in the liver important for energy production from fatty acids, that shows an unusual expression pattern in developing fetal mouse gonads. Shortly after gonadal sex determination it is up-regulated in the developing testes following a very similar spatial and temporal pattern as the male-determining gene Sry in Sertoli cells before switching to ovarian enriched expression. To test if Hmgcs2 is important for gonad development in mammals, we pursued two lines of investigations. Firstly, we generated Hmgcs2-null mice using CRISPR/Cas9 and found that these mice had gonads that developed normally even on a sensitized background. Secondly, we screened 46,XY DSD patients with gonadal dysgenesis and identified two unrelated patients with a deletion and a deleterious missense variant in HMGCS2 respectively. However, both variants were heterozygous, suggesting that HMGCS2 might not be the causative gene. Analysis of a larger number of patients in the future might shed more light into the possible association of HMGCS2 with human gonadal development.

The Potential Synergic Effect of a Complex Pattern of Multiple Inherited Genetic Variants as a Pathogenic Factor for Ovarian Dysgenesis: A Case Report

Non-syndromic primary ovarian insufficiency due to ovarian dysgenesis in 46,XX patients is an uncommon finding in the general population, even though several monogenic variants have been reported as causative factors. Here, we describe a 15-year-old patient diagnosed with gonadal dysgenesis possibly due to the interaction of three potentially pathogenic variants of genes involved in ovarian maturation, namely factor in the germline alpha (FIGLA), newborn ovary homeobox-encoding (NOBOX) and nuclear receptor subfamily 5 group A member 1 (NR5A1). We also describe a different degree of residual ovarian function within the proband's family, whose female members carry one to three demonstrated variations in the aforementioned genes in a clinical spectrum potentially dependent on the number of alleles involved. Our results support the hypothesis that the severity of the clinical picture of the proband, resulting in complete ovarian dysgenesis, may be due to a synergic detrimental effect of inherited genetic variants.

Germ Cell Tumors in Dysgenetic Gonads

This review describes the germ cell neoplasms that are malignant and most commonly associated with several types of gonadal dysgenesis. The most common neoplasm is gonadoblastoma, while others including dysgerminomas, yolk-sac tumors and teratomas are rare but can occur. The purpose of this review is to evaluate the incidences of these abnormalities and the circumstances surrounding these specific tumors.According to well-established methods, a PubMed systematic review was performed, to obtain relevant studies published in English and select those with the highest-quality data.Initially, the first search was performed using gonadal dysgenesis as the search term, resulting in 12,887 PubMed papers, published, from 1945 to 2017. A second search using ovarian germ cell tumors as the search term resulted in 10,473 papers, published from 1960 to 2017. Another search was performed in Medline, using germ cell neoplasia as the search term, and this search resulted in 7,560 papers that were published between 2003 to 2016, with 245 new papers assessing gonadoblastomas.The higher incidence of germ cell tumors in gonadal dysgenesis is associated with a chromosomal anomaly that leads to the absence of germ cells in these gonads and, consequently, a higher incidence of neoplasms when these tumors are located inside the abdomen. Several hypotheses suggest that increased incidence of germ cell tumors involves all or part of the Y chromosome or different genes.

GENETICS IN ENDOCRINOLOGY: Approaches to molecular genetic diagnosis in the management of differences/disorders of sex development (DSD): position paper of EU COST Action BM 1303 ‘DSDnet’

The differential diagnosis of differences or disorders of sex development (DSD) belongs to the most complex fields in medicine. It requires a multidisciplinary team conducting a synoptic and complementary approach consisting of thorough clinical, hormonal and genetic workups. This position paper of EU COST (European Cooperation in Science and Technology) Action BM1303 ‘DSDnet’ was written by leading experts in the field and focuses on current best practice in genetic diagnosis in DSD patients. Ascertainment of the karyotpye defines one of the three major diagnostic DSD subclasses and is therefore the mandatory initial step. Subsequently, further analyses comprise molecular studies of monogenic DSD causes or analysis of copy number variations (CNV) or both. Panels of candidate genes provide rapid and reliable results. Whole exome and genome sequencing (WES and WGS) represent valuable methodological developments that are currently in the transition from basic science to clinical routine service in the field of DSD. However, in addition to covering known DSD candidate genes, WES and WGS help to identify novel genetic causes for DSD. Diagnostic interpretation must be performed with utmost caution and needs careful scientific validation in each DSD case.

Essential Role of BRCA2 in Ovarian Development and Function

The causes of ovarian dysgenesis remain incompletely understood. Two sisters with XX ovarian dysgenesis carried compound heterozygous truncating mutations in the BRCA2 gene that led to reduced BRCA2 protein levels and an impaired response to DNA damage, which resulted in chromosomal breakage and the failure of RAD51 to be recruited to double-stranded DNA breaks. The sisters also had microcephaly, and one sister was in long-term remission from leukemia, which had been diagnosed when she was 5 years old. Drosophila mutants that were null for an orthologue of BRCA2 were sterile, and gonadal dysgenesis was present in both sexes. These results revealed a new role for BRCA2 and highlight the importance to ovarian development of genes that are critical for recombination during meiosis. (Funded by the Israel Science Foundation and others.).

New NR5A1 mutations and phenotypic variations of gonadal dysgenesis

Mutations in NR5A1 have been reported as a frequent cause of 46,XY disorders of sex development (DSD) associated to a broad phenotypic spectrum ranging from infertility, ambiguous genitalia, anorchia to gonadal dygenesis and female genitalia. Here we present the clinical follow up of four 46,XY DSD patients with three novel heterozygous mutations in the NR5A1 gene leading to a p.T40P missense mutation and a p.¹⁸DKVSG²²del nonframeshift deletion in the DNA-binding domain and a familiar p.Y211Tfs*83 frameshift mutation. Functional analysis of the missense and nonframeshift mutation revealed a deleterious character with loss of DNA-binding and transactivation capacity. Both, the mutations in the DNA-binding domain, as well as the familiar frameshift mutation are associated with highly variable endocrine values and phenotypic appearance. Phenotypes vary from males with spontaneous puberty, substantial testosterone production and possible fertility to females with and without Müllerian structures and primary amenorrhea. Exome sequencing of the sibling’s family revealed TBX2 as a possible modifier of gonadal development in patients with NR5A1 mutations.

A Biallelic Mutation in the Homologous Recombination Repair Gene SPIDR Is Associated With Human Gonadal Dysgenesis

CONTEXT

Primary ovarian insufficiency (POI) is caused by ovarian follicle depletion or follicle dysfunction, characterized by amenorrhea with elevated gonadotropin levels. The disorder presents as absence of normal progression of puberty.

OBJECTIVE

To elucidate the cause of ovarian dysfunction in a family with POI.

DESIGN

We performed whole-exome sequencing in 2 affected individuals. To evaluate whether DNA double-strand break (DSB) repair activities are altered in biallelic mutation carriers, we applied an enhanced green fluorescent protein-based assay for the detection of specific DSB repair pathways in blood-derived cells.

SETTING

Diagnoses were made at the Pediatric Endocrine Clinic, Clalit Health Services, Sharon-Shomron District, Israel. Genetic counseling and sample collection were performed at the Pediatric Genetics Unit, Schneider Children's Medical Center Israel, Petah Tikva, Israel.

PATIENTS AND INTERVENTION

Two sisters born to consanguineous parents of Israeli Muslim Arab ancestry presented with a lack of normal progression of puberty, high gonadotropin levels, and hypoplastic or absent ovaries on ultrasound. Blood samples for DNA extraction were obtained from all family members.

MAIN OUTCOME MEASURE

Exome analysis to elucidate the cause of POI in 2 affected sisters.

RESULTS

Analysis revealed a stop-gain homozygous mutation in the SPIDR gene (KIAA0146) c.839G>A, p.W280*. This mutation altered SPIDR activity in homologous recombination, resulting in the accumulation of 53BP1-labeled DSBs postionizing radiation and γH2AX-labeled damage during unperturbed growth.

CONCLUSIONS

SPIDR is important for ovarian function in humans. A biallelic mutation in this gene may be associated with ovarian dysgenesis in cases of autosomal recessive inheritance.

[Clinical and genetic features of 45,X maleness: A case report and review of the literature]

OBJECTIVE

To explore the relationship between the clinical and genetic features of a short-statured azoospermia male with the karyotype of 45,X.

METHODS

Using GTG-banded chromosome analysis, we performed karyotyping for a 150 cm-high infertile male with azoospermia and investigated the presence and location of the genes on the Y chromosome by FISH and PCR.

RESULTS

GTG-banded chromosome analysis showed the karyotype of the patient to be 45,X,add(14)(p11). The results of PCR manifested the deletion of AZFa, AZFb, AZFc, and AZFd in the SRY gene. FISH revealed the translocation of the short arm of the Y chromosome to that of chromosome 14 and deletion of most proportions of its long arm, with the disruption site close to the centromere region. The karyotype of the patient was 45,X,der(Y)t(Y;14)(q11;q11.2), 14.ish (SRY+, CEP Y+ , DYZ1－).

CONCLUSIONS

The karyotype of the patient was unbalanced Y/14 translocation. The SRY gene is the key to maleness. The deletion of AZFa－ d induces spermatogenic disturbance, and the deletion of the q arm of the Y chromosome may be related with short stature.

Effects of Chronic Irradiation at Low Doses on Morphological Indicators of Reproductive System of Dysgenic Female Drosophila melanogaster

In this paper the contribution of chronic irradiation at low doses (0.42 mGy/h) and dysgenesis to changing morphological parameters (gonadal atrophy/sterility and ovarian reserve) of the reproductive system of female Drosophild melanogaster is rated. It is shown that the sterilizing effect of dysgenesis is enhanced predominantly by irradiation of the maternal line. The level of ovarian reserve of irradiated females depends on the type of dysgenic system. Unlike I-R females in whom the level of radiation-induced ovarian reserve does not differ from the control, both decrease (in P-M females) and increase (in H-E females) is observed in the ovariole number. The results indicate the important role of mobile genetic elements destabilizing the genome in the modification of reproductive functions of females exposed to chronic-action of low-intensity γ-radiation.

Cytotype Regulation Facilitates Repression of Hybrid Dysgenesis by Naturally Occurring KP Elements in Drosophila melanogaster

P elements inserted in the Telomere Associated Sequences (TAS) at the left end of the X chromosome are determiners of cytotype regulation of the entire P family of transposons. This regulation is mediated by Piwi-interacting (pi) RNAs derived from the telomeric P elements (TPs). Because these piRNAs are transmitted maternally, cytotype regulation is manifested as a maternal effect of the TPs. When a TP is combined with a transgenic P element inserted at another locus, this maternal effect is strengthened. However, when certain TPs are combined with transgenes that contain the small P element known as KP, stronger regulation arises from a zygotic effect of the KP element. This zygotic effect is observed with transgenic KP elements that are structurally intact, as well as with KP elements that are fused to an ancillary promoter from the hsp70 gene. Zygotic regulation by a KP element occurs only when a TP was present in the maternal germ line, and it is more pronounced when the TP was also present in the grand-maternal germ line. However, this regulation does not require zygotic expression of the TP These observations can be explained if maternally transmitted piRNAs from TPs enable a polypeptide encoded by KP elements to repress P element transposition in zygotes that contain a KP element. In nature, repression by the KP polypeptide may therefore be facilitated by cytotype-mediating piRNAs.

MATTHEW-WOOD SYNDROME: A CASE WITH DEXTROCARDIA AND STREAK GONADS

Matthew-Wood syndrome (MWS), also termed Microphthalmia, syndrome 9 (MCOPS9, MIM 601186), Spear syndrome, or pulmonary hypoplasia, diaphragmatic hernia, anophthalmia and cardiac defects syndrome (PDAC syndrome), is an autosomal recessive disorder characterised by ocular, respiratory and cardiac abnormalities. Mutations in retinoic acid 6 gene (STRA6) have been reported in clinically diagnosed patients with MWS. Here we presented a case with MWS, who has characteristic findings of the syndrome as well as dextrocardia as an undescribed feature, and bilateral streak gonads which was described only in one patient previously. Molecular analysis showed a homozygous exonic missense mutation in the STRA6 gene.

Reproductive and obstetric outcomes in mosaic Turner's Syndrome: a cross-sectional study and review of the literature

BACKGROUND

Turner's syndrome (TS) is depicted as a total or partial absence of one X chromosome that results in ovarian dysgenesis. Chances of spontaneous pregnancy in TS are rare and the outcome of the pregnancies is known to be poor with an increased risk of miscarriage and stillbirths. Our aim is to evaluate reproductive and obstetric outcomes of natural conception and in-vitro fertilization (IVF) cycles in mosaic TS patients.

METHODS

A total of 22 mosaic TS cases (seventeen 45,X/46,XX and five 45,X/46,XX/47,XXX karyotypes) were evaluated.

RESULTS

Live birth and abortion rates were found as 32.7 % and 67.3 %, respectively in 52 pregnancies. Implantation, clinical pregnancy and take home baby rates were detected as 3.7 %, 8.6 % and 5.7 %, respectively per IVF cycle as a result of 35 cycles. Fecundability analysis revealed that 5 % of the cases experienced first pregnancy within 6 months and 8 % within the first 2 years. Mosaicism ratio did not have an effect on the time to the first pregnancy (p = .149).

CONCLUSION

Only a small proportion of the mosaic TS patients conceive in the first 2 years of the marriage. Age of menarche and age of marriage appear not to have any impact on the chance of conceiving. Mosaic TS cases should counseled about the low odds of pregnancy and high miscarriage rates.

Why Treat girls with Turner Syndrome with Growth Hormone? Growth and Beyond

Turner Syndrome (TS) is a rare disorder, characterized by numerous signs and symptoms, which are also highly variable in their expression in individuals. The understanding of the genetic basis of the phenotype has advanced greatly during the past decades. The most consistent features, which negatively affect the quality of life in these individuals, are short stature and impaired gonadal function. After recombinant human growth hormone (rhGH) became available and was shown to improve height, it was then approved and has been used widely. Yet it remains a challenge to decide on the optimal treatment modality for individuals with TS and to evaluate the benefits and risks also in terms of karyotype of GH on growth and on other organ systems. This article reviews some of the major aspects related to these issues.

[The rate of transposition and the specificity of transposable element insertions are not sufficient to cause gonadal dysgenesis in Drosophila melanogaster]

Data disputing the unique role of transposable elements (TEs) in the induction of intraspecific gonadal dysgenesis (GD) in Drosophila are discussed. Transposable elements (TEs) occupy the fifth part of the genome of Drosophila melanogaster.

Malformation syndromes associated with disorders of sex development

When embryological development of the internal and/or external genitalia is disrupted, the patient presents with a disorder of sex development (DSD) in the neonatal period or sometime later in life. Some of these patients have other, nongenital malformations, which makes their overall management more complex than if they just had a DSD. This Review summarises these malformation syndromes and discusses the recent research into their aetiology. The genetic causes of these malformation syndromes, when they are known, will also be described. Many specific genetic mutations are now known in malformation syndromes with a defect in hormonal function. By contrast, the genetic causes remain unknown in many nonhormonal morphological anomalies that affect the genitalia.

[P-M hybrid dysgenesis affects juvenile hormone metabolism in Drosophila melanogaster females]

This paper studies the metabolism of the juvenile hormone, which affects gonads functioning in Drosophila melanogasterfemales under P-M hybrid dysgenesis. It is shown that dysgenic females grown at 29°C have increased levels of the juvenile hormone (its degradation and stress reactivity are reduced), which apparently is a compensatory response to ovarian hypoplasia.

Genetic interactions between P elements involved in piRNA-mediated repression of hybrid dysgenesis in Drosophila melanogaster

Previous studies have shown that telomeric P elements inserted at the left end of the X chromosome are anchors of the P cytotype, the maternally inherited state that regulates P-element activity in the germ line of Drosophila melanogaster. This regulation is mediated by small RNAs that associate with the Piwi family of proteins (piRNAs). We extend the analysis of cytotype regulation by studying new combinations of telomeric and nontelomeric P elements (TPs and non-TPs). TPs interact with each other to enhance cytotype regulation. This synergism involves a strictly maternal effect, called presetting, which is apparently mediated by piRNAs transmitted through the egg. Presetting by a maternal TP can elicit regulation by an inactive paternally inherited TP, possibly by stimulating its production of primary piRNAs. When one TP has come from a stock heterozygous for a mutation in the aubergine, piwi, or Suppressor of variegation 205 genes, the synergism between two TPs is impaired. TPs also interact with non-TPs to enhance cytotype regulation, even though the non-TPs lack regulatory ability on their own. Non-TPs are not susceptible to presetting by a TP, nor is a TP susceptible to presetting by a non-TP. The synergism between TPs and non-TPs is stronger when the TP was inherited maternally. This synergism may be due to the accumulation of secondary piRNAs created by ping-pong cycling between primary piRNAs from the TPs and mRNAs from the non-TPs. Maternal transmission of P-element piRNAs plays an important role in the maintenance of strong cytotype regulation over generations.

Increased risk of gonadal malignancy and prophylactic gonadectomy: a study of 102 phenotypic female patients with Y chromosome or Y-derived sequences

STUDY QUESTION

What is the optimal protocol of management for phenotypic female patients with Y chromosome or Y-derived sequences, in particular for adult patients?

SUMMARY ANSWER

Immediate gonadectomy, long-term hormone therapy and psychological care are suggested to be the optimal management for older phenotypic female patients with Y chromosome or Y-derived sequences.

WHAT IS KNOWN ALREADY

Phenotypic female patients with Y chromosome or Y-derived sequences are at increasing risk of developing gonadal tumors with age. Early diagnosis and safe guidelines of management for these patients are needed.

STUDY DESIGN, SIZE, DURATION

One hundred and two phenotypic women with Y chromosome or Y-derived sequences were included in a straightforward, retrospective-observational study conducted over a period of 26 years from January 1985 to November 2010.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Patients aged 16-34 years presenting to our Academic Department of Gynecology with symptoms of disorders of sex development were subjected to history taking, hormonal evaluation, conventional cytogenetic analysis, PCR, histopathology and immunohistochemistry. Features of the gonads were examined and the outcome of prophylactic gonadectomy evaluated.

MAIN RESULTS AND THE ROLE OF CHANCE

Among the patients recruited in our study, 48 patients (47.1%) were diagnosed with complete/partial androgen insensitivity syndrome (CAIS/PAIS) (46XY), 33 cases (32.4%) with gonadal dysgenesis (46XY) and the remaining subjects (20.1%) with mixed gonadal dysgenesis (with sex chromosome structural abnormalities). The total incidence of malignancy was 17.6%. Seventeen patients (16.7%) had gonadoblastoma, while one patient (1.0%) with gonadal dysgenesis had dysgerminoma. Gonadoblastoma were observed in 2/21 patients with sex chromosome structural abnormalities (9.5%), 3/33 patients with gonadal dysgenesis (9.1%), 9/30 patients with CAIS (30.0%) and 3/18 patients with PAIS (16.7%).

LIMITATIONS, REASONS FOR CAUTION

Selection bias in this cohort study may affect data interpretation due to the low incidence of disorders of sex development in the general population.

WIDER IMPLICATIONS OF THE FINDINGS

The risk for malignant transformation may occur in early life and highly increase with age in patients with Y chromosome or Y-derived sequences. Optimal timing of gonadectomy should be decided by multiple factors including the subgroup of disorder, age and degree of patient's maturity. In addition, gonadal biopsy is suggested when the disease is diagnosed and any evidence of premalignancy warranties gonadectomy.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Key Scientific Research Project (2013CB967404), Natural Science Funds of Zhejiang Province (Y13H04005), Zhejiang Qianjiang talent plan (2013R10027), the Fundamental Research Funds for the Central Universities and Key Projects in the National Science & Technology Pillar Program during the Eleventh Five-Year Plan Period (2012BAI32B04). The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER None.

[Induction of transpositions of hobo-elements in chronically irradiated cells of dysgenetic and non-dysgenetic individuals of Drosophila melanogaster]

This paper studies the effect of chronic γ-radiation of different intensities on the induction of hobo-elements in cells ofdysgenetic and non-dysgenetic drosophila species. The level of gonadal atrophy, DNA damage, and mutability of the mini-white locus is estimated. It is shown that the frequency of displacements of the hobo-elements increases with the increase in the chronic irradiation dose, where an essential role belongs to the maternal effect. The level of DNA damage in the cells of embryos and larvae varies and depends on the conditions of induction of hobo-transposons. Analysis of the PCR products showed that chronic irradiation in a certain range of accumulated doses is able to induce formation of new copies of the hobo-elements. At the same time, the structure of deleted hobo-sequences may vary in response to higher doses of irradiation.

[Effect of sex inversion in embryos of domestic chicken (Gallu gallus domesticus) by influence of letrozole and tamoxifen]

Realization of program of sex formation in multicellular organisms is a complex multistage process. The role of the inductor in this process is assigned to sex hormones synthesized by cells of the emerging gonads. The action of androgens on the formation of the male is now well understood. However, little is known about the involvement of estrogen the female gonad formation and the formation of a female as a whole. Here we present the results of experimental sex inversion in female chickens produced by aromatase inhibition and by the action of tamoxifen on chicken embryos. We have shown various masculinizing effect depending on the dose of active substance and the number of injections. We have noted that inhibition of aromatase does not block meiotic prophase in oogoniums. We have suggested that there are differences in the mechanisms of action of retinoic acid and estrogens on oogenesis. We have first shown proteins and nucleoproteins that interact with the estrogen receptor 1 and provided maps of their gene localization in human and chicken genomes.

Identification of a novel androgen receptor mutation in a family with multiple components compatible with the testicular dysgenesis syndrome

CONTEXT

Androgen signaling via the androgen receptor (AR) is essential for normal testis development and male reproductive functions. We describe a rare family with 3 males affected by a mild disorder of sex determination compatible with testicular dysgenesis syndrome (TDS), including subfertility, cryptorchidism, hypospadias, and testicular cancer, caused by a novel AR mutation.

OBJECTIVE

The aim of this study was to describe the phenotype of the affected males, characterize functionally the novel AR mutation, and discuss the significance of partial androgen insufficiency in the pathogenesis of TDS.

PARTICIPANTS

The proband, his first cousin, and a nephew underwent a detailed clinical investigation including genetic tests, whereas four female members of the family were tested for the specific AR mutation.

RESULTS

A novel AR mutation, c.2214T>G;p.Ile738Met, was identified in the affected family members. Functional analysis of the mutation in a gene-reporter assay showed a 50% reduction in AR-induced transcriptional activity. The affected males had elevated LH and T in accordance with decreased AR signaling. The histology and immunohistochemical profile of the testis tissue from the 2 patients with testicular cancer showed features consistent with insufficient testis development and TDS.

CONCLUSION

The presence of all hallmarks of TDS, including germ cell cancer, in a family with a novel AR mutation causing a partial decrease in AR function is in line with the concept that reduced androgen signaling may contribute to the development of TDS. It also seems consistent with the hypothesis that environmental factors interfering with this pathway can play a role in the pathogenesis of TDS.

Duplication of dosage sensitive sex reversal area in a 46, XY patient with normal sex determining region of Y causing complete sex reversal

BACKGROUND

The sex chromosome composition of the primordial gonad, either 46XX or 46XY, determines its differentiation as ovaries or testes. Local hormones secreted by developing gonads and tissue specific transcription factors influence the differentiation of external and internal genital structures. Dosage sensitive sex reversal adrenal hypoplasia congenita critical region (DAX1) on Xp21 is a gene which is expressed in the developing adrenals, gonads, hypothalamus and pituitary gland. Duplication of this area causes dosage sensitive male-to-female sex reversal while mutation or deletion leads to adrenal hypoplasia congenita with hypogonadotropic hypogonadism in affected males.

AIM

To report a case with duplication of the X chromosome segment within the region of Xp21.1-22.2 resulting in 46 XY sex reversal and a literature review on DAX1 and dosage sensitive sex reversal (DSS).

METHODS AND RESULTS

We present the clinical history, physical findings, laboratory, and imaging study results in a newborn baby. This infant was sex assigned as female at birth and had normal female external genitalia. Chromosome analysis was done due to multiple minor malformations and showed a karyotype of 46 Xp+Y. Fluorescent in situ hybridization analysis revealed the duplication in the DSS area.

CONCLUSION

Duplication of the DAX1 gene on the X chromosome with normal sex determining region of Y (SRY) results in 46 XY sex reversal. This was inherited from the mother who had normal ovarian function. Additional problems include growth failure, mental retardation and multiple congenital anomalies. The baby did not have a mutation or deletion of DAX1, which would have caused adrenal insufficiency and hypogonadism.

[Congenital disorders of gonadal differentiation: clinico-morphological variants and surgical treatment]

The article presents the results of examination and surgical treatment of 25 patients with congenital disorders of gonadal differentiation. Survey plan included an assessment of the external genitalia, karyotyping and molecular analysis of Y-chromosome, determination of serum gonadotropins and testosterone levels, visualization of the gonads using ultrasound and laparoscopy methods, and intraoperative morphological examination of the material. Based on the results of a comprehensive survey, mixed testicular dysgenesis was identified in 25% of patients, complete testicular dysgenesis--in 16%, partial gonadal dysgenesis--in 44%, ovotesticular violation of sexualization--in 16% of patients. Clinical, macroscopic and morphological characteristics of each of these options are defined. The choice of sexual identity and tactics of surgical treatment are explained.

Correlation of intercentromeric distance, mosaicism, and sexual phenotype: molecular localization of breakpoints in isodicentric Y chromosomes

Isodicentric chromosomes are among the structural abnormalities of the Y chromosome that are commonly identified in patients. The simultaneous 45,X cell line that is generated in cell division due to instability of the isodicentric Y chromosome [idic(Y)] has long been hypothesized to explain the variable sexual development of these patients, although gonads have been studied in only a subset of cases. We report here on the molecular localization of breakpoints in ten patients with an idic(Y). Breakpoints were mapped by FISH using BACs; gonads and fibroblasts were also analyzed when possible to evaluate the level of mosaicism. First, we demonstrate great tissue variability in the distribution of idic(Y). Second, palindromes and direct repeats were near the breakpoint of several idic(Y), suggesting that these sequences play a role in the formation of idic(Y). Finally, our data suggest that intercentromeric distance has a negative influence on the stability of idic(Y), as a greater proportion of cells with breakage or loss of the idic(Y) were found in idic(Y) with a greater intercentromeric distance. Females had a significantly greater intercentromeric distance on their idic(Y) than did males. In conclusion, our study indicates that the Y chromosome contains sequences that are more prone to formation of isodicentric chromosomes. We also demonstrate that patients with an intercentromeric distance greater than 20 Mb on their idic(Y) are at increased risk of having a female sexual phenotype.

[Testicular dysgenesis syndrome: an update]

Researches on the testicular dysgenesis syndrome (TDS) have flourished in the recent decade, and a widely accepted view on its pathogenesis is that environmental endocrine disrupting chemicals (EDCs) act on Leydig cells and/or testicular Sertoli cells, resulting in abnormal development of the testis and leading to the symptoms of TDS. Molecular biological studies suggest a correlation of TDS etiology with insulin-like factor 3 (INSL-3), androgen receptor (AR), P27kip, WT-1 and Müllerian inhibiting substance (MIS). This review focuses on the progress in current researches on the etiology and mechanism of TDS.

Gonadal mosaicism of a TAZ (G4.5) mutation in a Japanese family with Barth syndrome and left ventricular noncompaction

TAZ (G4.5) was initially identified as the gene associated with Barth syndrome and left ventricular noncompaction (LVNC). The purpose of this study was to investigate patients with LVNC for disease-causing mutations in TAZ. In 124 Japanese patients, including 50 families, mutation analysis of TAZ was performed using DNA sequencing. A splice donor mutation was identified in two brothers with Barth syndrome and LVNC, and a sister who was asymptomatic. However, the variant was not identified in either parent or the maternal grandparents, all of whom were asymptomatic. Due to the recurrent inheritance of this variant by each of the children we concluded that this was evidence of gonadal mosaicism in the obligate carrier mother, the first reported occurrence of this in Barth syndrome.

[Dynamics of gonadal dysgenesis frequency in Drosophila melanogaster under controlled conditions of chronic radiation exposure]

Two Drosophila melanogaster strains (Canton-S and ri-lines) for 20 generations were in the controlled terms of chronic irradiation with 3-dose rate (1,2 x 10(-8); 0,3 x 10(-8); 0,12 x 10(-8) Gy/c). The dynamics of hybrid dysgenesis frequency was explored for each generation of F1 descendants from Canton-S and ri-lines crossing. The gradual change of dose response of hybrid dispense depending on duration of irradiation of ancestors and dose rate was shown. The complex dynamics of hybrid dysgenesis frequency depending on irradiation duration of ancestors and dose rate was detected. The cumulative effect of the prolonged irradiation shows up as adaptation at the lowest dose rate and as exhaustion at the highest dose rate. Question comes into discussion about the features of transitional process and including of protective and adaptive reactions hierarchy at the conditions of radiation factor chronic action.

Control of sex development

The process of sexual differentiation is central for reproduction of almost all metazoan, and therefore, for maintenance of practically all multicellular organisms. In sex development, we can distinguish two different processes, sex determination, that is the developmental decision that directs the undifferentiated embryo into a sexually dimorphic individual. In mammals, sex determination equals gonadal development. The second process known as sex differentiation takes place once the sex determination decision has been made through factors produced by the gonads that determine the development of the phenotypic sex. Most of the knowledge on the factors involved in sexual development came from animal models and from studies of cases in whom the genetic or the gonadal sex does not match the phenotypical sex, that is, patients affected by disorders of sex development (DSDs). Generally speaking, factors influencing sex determination are transcriptional regulators, whereas factors important for sex differentiation are secreted hormones and their receptors. This review focuses on these factors and whenever possible, references regarding the 'prismatic' clinical cases are given.

Mixed gonadal dysgenesis in a 45,X neonate with chromosome Y material in the dysgenetic gonad

We report on a neonate with a disorder of sex development, Prader 3-4 external genitalia and a palpable structure in the right inguinal canal suggestive of gonadal tissue. Chromosome studies on blood lymphocytes showed monosomy of chromosome X. Laparoscopy identified a streak-like gonad on the left side, unicorn uterus and a dysgenetic testis on the right, attached to a Fallopian tube. Because of the unilateral palpable gonad and the presence of ambiguous genitalia we investigated further for the presence of Y material. Quantitative fluorescent PCR analysis of material from the dysgenetic gonad and skin fibroblasts revealed the presence of chromosome Y-derived sequences, suggesting sex chromosome mosaicism. In 45,X/46,XY mosaicism, chromosome studies carried out on peripheral lymphocytes do not always reflect the proportion of cell lines in the gonads. The detection of Y chromosome material in a dysgenetic gonad is extremely significant, due to the high risk of malignant transformation.

Testicular dysgenesis syndrome: foetal origin of adult reproductive problems

The evidence for the existence of testicular dysgenesis syndrome (TDS) is presented in this review. Several epidemiological studies have shown that conditions like cryptorchidism, impaired spermatogenesis, hypospadias and testicular cancer can be associated as risk factors for each other. Thus, the risk of testis cancer is significantly increased in men with cryptorchidism and/or infertility. Several recent studies point towards early dysgenesis of the foetal testis as the biological link between these disorders. Dysgenesis has been demonstrated in biopsies of the contralateral testis of men with testis cancer and in infertile men. The histological evidence includes immature seminiferous tubules with undifferentiated Sertoli cells, microliths and Sertoli-cell only tubules. Dysgenetic testes often have an irregular ultrasound pattern, where microliths may also be visible. Our current hypothesis is that maternal exposure to endocrine disrupting chemicals may contribute to the pathogenesis of TDS. Animal experiments have shown that all TDS symptoms, except testicular cancer, can be induced by foetal exposure to anti-androgenic chemicals. However, the cause of TDS in humans remains to be determined.

Familial frameshift SRY mutation inherited from a mosaic father with testicular dysgenesis syndrome

CONTEXT

The SRY gene encodes a transcription factor responsible for initiating testis differentiation. Mutations in SRY almost always result in XY sex reversal with pure gonadal dysgenesis and an increased risk of gonadal tumor. Most of these mutations are de novo, affecting only one individual in a family. Only a small subset of mutations is shared between a phenotypically normal father and one or more of his affected children. Incomplete penetrance and somatic mosaicism are two hypotheses that may explain a normal phenotype in a father carrying a SRY mutation.

PATIENTS AND RESULTS

We describe a family with two sisters with XY sex reversal and pure gonadal dysgenesis and a phenotypically normal brother. A novel constitutional frameshift SRY mutation was identified in both sisters and was absent in the brother. The single base pair deletion (c.71delA) led to a premature stop codon in position 60 of the protein, removing entirely the high-mobility group domain and the DNA-binding domain of SRY. The father of the three children presented with hypospadias; cryptorchidism; testicular seminoma and oligoasthenozoospermia, an association termed testicular dysgenesis syndrome (TDS); and the SRY mutation in a mosaic state in the peripheral blood and the tumor.

CONCLUSIONS

This observation of somatic and germinal mosaicism for a SRY mutation may explain the variable penetrance in some familial gonadal dysgenesis. Importantly, the present report is the first one describing the association of SRY mutation in a male with TDS. This suggests that mutations in a sex-determining gene may contribute to the pathogenesis of TDS.

[Disorders of sex differentiation: genes responsible for development of genital system and final phenotype]

OBJECTIVE

The study summarizes data on genes responsible for development of gonads and subsequently of additional structures of genital system in humans. It comprises the effect of gene defects on clinical phenotype.

SUBJECT

Review article.

SETTING

Department of Pediatrics, University Hospital Motol and 2nd Faculty of Medicine, Charles University in Prague.

SUBJECT AND METHOD

We present the overview of genes that contribute to development of genital system. Special emphasis is given on patient's phenotype related with various genetic disorders. Data were mainly found on Pubmed or OMIM web-sites according to key words "sex development" and "sex determination". We focused on ten genes with known relation to gonadal development--SRY, SOX9, SF1, DAX1, WNT4, WT1, DMRT1, DHH, RSPO1, ATRX.

CONCLUSION

Sex development is a complex process orchestrated by numerous genes. Here we collect information on gene defect (gene mutations or defective number of gene copies) that cause gonadal maldevelopment with effects on final phenotype. Currently, genetic background of numerous disorders can be detected. That allows not only to verify the diagnosis but also to predict the future sexual development and genetic risk for other family members.

Loss of cytochrome P450 17A1 protein expression in a 17alpha-hydroxylase/17,20-lyase-deficient 46,XY female caused by two novel mutations in the CYP17A1 gene

17alpha-Hydroxylase deficiency (17OHD) is a rare form of congenital adrenal hyperplasia caused by mutations in the CYP17A1 gene. This condition shows considerable clinical and biochemical variation. Molecular characterization of novel mutations in the CYP17A1 gene and detailed study of their structural, enzymatic, and clinical consequences are required to fully understand enzyme behavior. Here, we present the first molecular characterization of two novel mutations in CYP17A1 in a 15-year-old female Mexican mestizo 46,XY female with primary amenorrhea and lack of pubertal development and severe hypertension that manifested only after surgery. A complete clinical and biochemical evaluation was compatible with 17OHD. Structural anomalies in the CYP17A1 gene were discovered by direct automated sequencing, which revealed a novel compound heterozygous K110X/R362H mutation that leads to a complete lack of enzyme activity. Immunohistochemical analyses performed to determine protein expression and localization showed that cytochrome P450 17A1 was completely absent in the patient's testicular tissue. Studies of novel mutations, such as those described here, provide important information that allows us to better understand the effect of a given mutation on enzyme function and to observe the impact of the mutation on clinical phenotype.

[Molecular and cytogenetic study on 5 cases with gonadal dysgenesis: clinical applications of fluorescence in situ hybridization(FISH) and BAC-FISH]

OBJECTIVE

To explore the applications of fluorescence in situ hybridization (FISH) in the diagnosis for the patients with gonadal dysgenesis.

METHODS

After routine gynecologic examination, ultrasonography and endocrine examination, 5 cases of gonadal dysgenesis and hypogonadism were analyzed by using chromosomal diagnoses including G-banding, Q-banding, multiplex FISH and BAC-FISH analyses.

RESULTS

Among the 5 cases of gonad agenesis patients, 2 were pure gonadal dysgenesis with 46, XY karyotype, 3 were mixed gonadal dysgenesis with mos 45, X/47, XXX; 45, X/46, XY or 46, X, der(Y) karyotype.

CONCLUSION

Sex chromosomal abnormalities resulted in gonadal dysgenesis symptoms. Applications of FISH and BAC-FISH analyses can correctly diagnose the sex chromosomal abnormalities for patients with gonad agenesis and provide accurate medical genetic data for clinical diagnosis and therapy.

46 XY pure gonadal dysgenesis with gonadoblastoma and dysgerminoma

BACKGROUND

Swyer syndrome is a distinct type of pure gonadal dysgenesis characterized by a 46 XY karyotype in female phenotypic patients. It shows an abnormality in testicular differentiation. It is usually revealed by primary amenorrhea. The tumor that usually develops in Swyer syndrome is gonadoblastoma. Although gonadoblastoma is considered benign, the risk of malignant germ cell tumor development is high.

OBJECTIVE

The aim of this report is to stress on the risk of occurrence of malignant germ cell tumors on these dysgenesic gonads.

CASE REPORT

We present the clinical, sonographic and endocrine findings in the case of a 13 year-old phenotypic young girl with a 46 XY karyotype and gonadal dysgenesis. The patient underwent surgery for adnexal torsion. An examination of the gonads revealed gonadoblastoma associated to dysgerminoma. The treatment and the follow up are detailed.

CONCLUSION

The presence of Y chromosome in the karyotype of a patient presenting a gonadal dysgenesis must lead to prophylactic bilateral gonadectomy in order to avoid a malignant transformation. Gonadectomy must be followed by a hormone replacement therapy.

[Identification of potential neoplastic risk in gonadal development abnormality with Y chromosome of 79 cases]

OBJECTIVE

To identify the potential neoplastic risk in gonadal development abnormality with Y chromosome.

METHODS

Inquiries about the illness history were made. Lymphocyte chromosomal karyotype of peripheral blood was analyzed. Sex determining region Y gene and relative steroids and enzymes were detected. Gonadal site was examined through medical imaging. Gonadal excision was performed by laparotomy or laparoscopy. Pathological examinations were done on all of the specimens.

RESULTS

Among 41 cases of androgen insensitive syndrome, spermatogenic cell neoplasm occurred in 1 patient, sertoli cell tumor in 2, and interstitial cell hyperplasia in 5. Among 14 cases of 17 alpha-hydroxylase deficiency (XY) syndrome, one was sertoli cell tumor, and one was sertoli cell hyperplasia. In 4 cases of XY pure gonadal dysgenesis, one was gonadoblastoma with dysgerminoma. One of 16 cases of XO/XY gonadal dysgenesis was spermatogenic cell neoplasm with agenda cell tumor. Four cases of testes degeneration were all with dysgenetic testes. All of the gonadoblastoma and germ-cell tumor were located in the pelvis. Tumors occurred mostly during 15 years of age to 32 years.

CONCLUSIONS

The gonads of XY pure gonadal dysgenesis has high risks of gonadoblastoma and germ-cell tumor. The older the onset age after puberty, the higher the malignancy risk is. Once diagnosed, bilateral gonads should be excised as soon as possible.

Estrogen receptor alpha is a major contributor to estrogen-mediated fetal testis dysgenesis and cryptorchidism

Failure of the testes to descend into the scrotum (cryptorchidism) is one of the most common birth defects in humans. In utero exposure to estrogens, such as 17beta-estradiol (E2) or the synthetic estrogen diethylstilbestrol (DES), down-regulates insulin-like 3 (Insl3) expression in embryonic Leydig cells, which in turn results in cryptorchidism in mice. To identify the molecular mechanism whereby xenoestrogens block Insl3 gene transcription, we performed a microarray analysis of wild-type or estrogen receptor (ER) alpha-mutant testes exposed in utero to pharmacological doses of E2 or DES. Six and 31 genes were respectively down-regulated and up-regulated by estrogen exposure (> or =4-fold). All six genes down-regulated by estrogen exposure, including Insl3 and the steroidogenic genes steroidogenic acute regulatory protein and cytochrome P450 17alpha-hydroxylase/17,20-lyase, were done so by an ERalpha-dependent mechanism. In contrast, up-regulation was mediated either by ERalpha for 12 genes or by an independent mechanism for the 19 remaining genes. Finally, we show that Insl3 gene expression and testicular descent were not affected by in utero exposure to E2 or DES in ERalpha mutant mice, whereas absence of ERbeta did not influence the effect of these estrogens. Collectively, these data demonstrate that xenoestrogens inhibit the endocrine functions of fetal Leydig cells through an ERalpha-dependent mechanism.

Tumor risk in disorders of sex development (DSD)

Disorders of sex development (DSD), previously referred to as intersex disorders, comprise a variety of anomalies defined by congenital conditions in which chromosomal, gonadal, or anatomical sex is atypical. Besides issues such as gender assignment, clinical and diagnostic evaluation, surgical and psychosocial management, and sex steroid replacement, the significantly increased risk for developing specific types of malignancies is both clinically and biologically relevant. This relates to germ-cell tumors specifically in DSD patients with hypovirilization or gonadal dysgenesis. The presence of a well-defined part of the Y chromosome (known as the GBY region) is a prerequisite for malignant transformation, for which the testis-specific protein on the Y chromosome (TSPY) is a likely candidate gene. The precursor lesions of these cancers are carcinoma in situ (CIS)/intratubular germ-cell neoplasia unclassified (ITGCNU) in testicular tissue and gonadoblastoma in those without obvious testicular differentiation. Most recently, undifferentiated gonadal tissue (UGT) has been identified as the likely precursor for gonadoblastoma. The availability of markers for the different developmental stages of germ cells allows detailed investigation of the characteristics of normal and (pre)malignant germ cells. Although informative in a diagnostic setting for adult male patients, these markers - such as OCT3/4 - cannot easily distinguish (pre)malignant germ cells from germ cells showing delayed maturation. This latter phenomenon is frequently found in gonads of DSD patients, and may be related to the risk of malignant transformation. Thus, the mere application of these markers might result in over-diagnosis and unnecessary gonadectomy. It is proposed that morphological and histological evaluation of gonadal tissue, in combination with OCT3/4 and TSPY double immunohistochemistry and clinical parameters, is most informative in estimating the risk for germ-cell tumor development in the individual patient, and might in future be used to develop a decision tree for optimal management of patients with DSD.

Environment, testicular dysgenesis and carcinoma in situ testis

The testicular dysgenesis syndrome (TDS) hypothesis proposes that a proportion of the male reproductive disorders-cryptorchidism, hypospadias, infertility and testicular cancer-may be symptoms of one underlying developmental disease, TDS, which is most likely a result of disturbed gonadal development in the embryo. TDS may be caused by genetic factors, environmental/life-style factors, or a combination of both. Some rare disorders of sex development of genetic origin are among the best-known examples of severe TDS. Among the environmental and life-style factors that are suspected to influence the hormonal milieu of the developing gonad are the endocrine disrupters. A prenatal exposure to commonly used chemicals, e.g. phthalates, may result in a TDS-like phenotype in rats. Currently, this animal model is the best model for TDS. In humans the situation is much more complex, and TDS exists in a wide range of phenotypes: from the mildest and most common form, in which impaired spermatogenesis is the only symptom, to the most severe cases, in which the patient may develop testicular cancer. It is of great importance that clinicians in different specialties treating patients with TDS are aware of the association between the different symptoms.

Cytotype regulation by telomeric P elements in Drosophila melanogaster: interactions with P elements from M' strains

P strains of Drosophila are distinguished from M strains by having P elements in their genomes and also by having the P cytotype, a maternally inherited condition that strongly represses P-element-induced hybrid dysgenesis. The P cytotype is associated with P elements inserted near the left telomere of the X chromosome. Repression by the telomeric P elements TP5 and TP6 is significantly enhanced when these elements are crossed into M' strains, which, like P strains, carry P elements, but have little or no ability to repress dysgenesis. The telomeric and M' P elements must coexist in females for this enhanced repression ability to develop. However, once established, it is transmitted maternally to the immediate offspring independently of the telomeric P elements themselves. Females that carry a telomeric P element but that do not carry M' P elements may also transmit an ability to repress dysgenesis to their offspring independently of the telomeric P element. Cytotype regulation therefore involves a maternally transmissible product of telomeric P elements that can interact synergistically with products from paternally inherited M' P elements. This synergism between TP and M' P elements also appears to persist for at least one generation after the TP has been removed from the genotype.

Impact of the Y-containing cell line on histological differentiation patterns in dysgenetic gonads

OBJECTIVE

Gonadal karyotyping is considered a tool for increasing our knowledge of disturbed gonadal development in patients with gonadal dysgenesis and for estimating more accurately the risk for gonadoblastoma formation. The objective was to gain insight into the role of Y chromosome distribution in the histological heterogeneity of gonads of patients with gonadal dysgenesis.

DESIGN

Investigation of the possible relationship between peripheral blood karyotype, gonadal karyotype, morphological differentiation patterns of dysgenetic gonads and tumour formation.

PATIENTS

In total 22 gonadal samples from 19 patients with gonadal dysgenesis (45,X/46,XY and variants n = 14; 46,XY: n = 3; 46,XX: n = 2) were examined.

MEASUREMENTS

Morphological examination and immunohistochemical staining for testis specific protein, Y encoded (TSPY) and fluorescent and nonfluorescent in situ hybridization directly on gonadal tissue.

RESULTS

No correlation was observed between peripheral blood karyotype and gonadal karyotype or between gonadal karyotype and the corresponding differentiation pattern. A Y-containing cell line in Sertoli cells was encountered no more frequently than were other cell types.

CONCLUSIONS

The distribution of the Y-containing cell line in peripheral blood is not a suitable indicator for predicting the histological differentiation pattern found in the gonads of patients with gonadal dysgenesis. The analysis of Y-containing cell lines in the gonads of such patients could be informative with regard to the specific characteristics of gonadal development in humans as compared to chimeric mouse models. Moreover, it is essential to understand the mechanisms underlying disturbed gonadogenesis in these patients. As the gonadal karyotype is not related to the encountered gonadal differentiation pattern, it does not allow prediction of the risk for gonadoblastoma formation.

R-spondins in cutaneous biology: nails and cancer

The R-spondins are a relatively recently identified family of secreted proteins linked to the Wnt signaling pathway. Recently, human phenotypes have been associated with mutations in two human R-spondins. Germline RSPO4 and RSPO1 mutations result in recessive anonychia (absence of all fingernails and toenails) and a recessive syndrome with XX-male sex reversal, PPK and a predisposition to SCC, respectively. This review discusses the key roles R-spondins play in embryogenesis, adult tissue maintenance and skin carcinogenesis.

Distribution of sex chromosomes in dysgenetic gonads of mixed type

In a four-week-old child with female external and internal genitalia but with clitoris hypertrophy chromosome analysis from blood lymphocytes revealed a 46,XY karyotype. No deletion of Y chromosomal sequences was detected by PCR analysis of genomic DNA isolated from peripheral blood leucocytes. Because of the increased risk for gonadal tumours, gonadectomy was performed. Conventional cytogenetic analysis of the left dysgenetic gonad revealed a gonosomal mosaicism with a 45,X cell line in 27 of 50 metaphases. The dysgenetic left gonad demonstrated a significantly higher proportion (P = 0.005) of cells carrying a Y chromosome (46.3%) than the streak gonad from the right side (33.9%). Histomorphological examination of the left gonad revealed immature testicular tissue and rete-like structures as well as irregular ovarian type areas with cystic follicular structures. Interphase FISH analysis of the different tissues of this dysgenetic gonad demonstrated variable proportions of cells with an X and a Y chromosome. Whereas Sertoli cells and rete-like structures revealed a significantly higher proportion of XY cells in relation to the whole section of the dysgenetic gonad (P < 0.0001), almost all granulose-like cells carried no Y chromosome. The proportion of XY/X cells in theca-like cells and Leydig cells was similar to that of the whole dysgenetic gonad. In contrast to these findings, spermatogonia exclusively contained an XY constellation.

Case report of two siblings with familial ovarian dysgenesis

Two sisters were admitted separately at different times (ages 15 and 12 years, respectively) to our unit because of amenorrhea, lack of secondary sex characteristics, and short stature. No evidence of other congenital anomalies was found. Laboratory studies indicated hypergonadotropic hypogonadism. Peripheral blood samples revealed normal 46,XX karyotype for both patients. No gonads were visualized by ultrasonography. The two cases underline the need to take familial ovarian dysgenesis into consideration in female patients with short stature, lack of secondary sex characteristics, normal karyotypes, and similar sibling histories.